The bird with the broken neck is the symbol of such abuse.
The bird represented the woman's freedom and something she wanted to have one day. It was constantly in a cage, like she was in her house married to an abusive husband. Even though he was not physically abusive towards her, the mental abuse was unbearable which is why she killed him.
Society runs better with both laws and leaders, and man is nor good or evil.
The excerpt given above is taken from Phillis Wheatley's poem "On Being Brought from Africa to America". The word sable literally means color black. In this line, Wheatley uses the word "sable" to indicate sense of inferiority. The author is an African and their race color is different from the rest.
(sorry if im wrong)
I’ve never read the novel but u can ask google or insert an image of text